Descaling device

ABSTRACT

Apparatus for descaling wire. There is provided wet abrasive grit blasting means particularly adapted for descaling an elongated workpiece of generally rounded cross section, such as rod or wire. Said means contemplate placing at the discharge end of a generally conventional venturi tube into which a blasting slurry is introduced and through which the workpiece is coaxially led, one or more process means comprising serially connected chambers of repetitively varying cross section. In the illustrated embodiment each of said chambers includes a first portion of relatively large diameter, a second portion of converging diameter and a third portion of relatively small diameter. Same causes repeated slowing and acceleration of abrasive fluid flow together with repetitive expansion and contraction of the carrying gas, all of which generates a high degree of random turbulence and uniform action thereof onto the workpiece.

1 1 Sept. 23, 1975 1 DESCALING DEVICE [75] Inventor: Shigeharu KobayashLShimotogari.

Japan [73] Assignee: Fuji Seiki Machine Works, Ltd.,

Shizuoka Prefecture, Japan [22] Filed: Oct. 17. I974 [2]] Appl. No.: 515,671

2.621.446 12/1952 Russell r r .4 51/14 2666279 1/1954 Chalom 5 1/11 3.362.109 1/1968 Wallace 4 .4 51/14 X 3.48LO80 12/1969 Davidson 51/14 X FOREIGN PATENTS OR APPLICATIONS 1,234.680 6/1971 United Kingdom 4. 51/14 Primary Examiner-Donald G. Kelly Attorney. Agent, or Fi'rmWoodhams. Blanchard and Flynn [57] ABSTRACT Apparatus for descaling wire. There is provided wet abrasive grit blasting means particularly adapted for descaling an elongated workpiece of generally rounded cross section. such as rod or wire. Said means contemplate placing at the discharge end of a gener ally conventional venturi tube into which a blasting slurry is introduced and through which the workpiece is coaxially led, one or more process means comprising serially connected chambers of repetitively varying cross section. In the illustrated embodiment each of said chambers includes a first portion of relatively large diameter. a second portion of converging diame ter and a third portion of relatively small diameter. Same causes repeated slowing and acceleration of abrasive fluid flow together with repetitive expansion and contraction of the carrying gas. all of which generates a high degree of random turbulence and uniform action thereof onto the workpiece.

5 Claims. 3 Drawing Figures DESCALING DEvICE FIELD OF THE INVENTION The invention relates to apparatus for descaling an elongated material, such as wire, and particularly to a type thereof utilizing abrasive or wet abrasive blasting methods for this purpose.

BACKGROUND OF THE INVENTION In the descaling of elongated material. such as wire. rod. or other elongated material having a generally round cross section. it is highly essential that the abrasive material be caused to impinge upon the workpiece uniformly around the entire surface thereof. On the other hand, where a slurry comprising a carrying liquid and abrasive grit enters a chamber through which the workpiece passes for treatment. there is a considerable tendency for the grit to impinge upon the workpiece in a somewhat concentrated manner. either concentrating on the side from which the slurry enters into such chamber, occasionally on the opposite side thereof where the flow is subjected to reversal. and sometimes the concentration migrates from place to place as the turbulence within the treating chamber varies. Nevertheless such concentration often exists and prevents the accomplishment of uniform work. It is therefore still highly desirable. in spite of the large amount of work which has already been carried out in this field. to provide means by which a flow of abrasive grits and a carrying liquid can be applied to a traveling elongated workpiece. such as a wire and particularly one of round cross section. in a manner which will provide for continuously uniform impingement by the abrasive grit onto the workpiece uniformly from all sides thereof.

BRIEF DESCRIPTION OF THE DRAWINGS SUMMARY OF THE INVENTION The invention comprises means for conducting an elongated workpiece. as a wire. through a venturi and then through a succession of large and small chambers. Abrasive grit and a suitable liquid carrier are introduced into a chamber ahead of said venturi guided thereby around the wire and then pass to said succession of large and small chambers. These large and small chambers completely break up any tendency for the slurry to flow in a laminar or other patterned manner and instead assure a completely random turbulence. This ensures that the particles of grit contained within the slurry will impinge upon the wire in a completely random manner and therefore substantially uniformly around its entire surface.

DETAILED DESCRIPTION Referring first to FIG. I there is provided a housing I defining a chamber 2 of circular cross sectionv Cen tered within said chamber is a nozzle 3 whosec tip 4 tapers convcrgingly to define the commencement of a venturi in cooperation with the similarly converging outlet opening 6 from the chamber 2. An air inlet 7 supplies a carrying gas, as compressed air, to a chamber 8, said gas then flowing through the hollow center 9 of the nozzle 3. The workpiece W. here a wire of round cross section. enters through a suitable bushing 11, passes coaxially through the nozzle 3 and on through the rest of the apparatus. An inlet fitting [2 provided with inlet passageway 13 introduces the abrasive slurry into the chamber 2 from any convenient external source. not shown.

The housing 1 in this embodiment is provided with an annular flange 14 at the discharge end thereof into which is received the venturi tube I6. Within said tube there is provided a passageway 17 coaxial with the opening 6 from the housing I, the portion 17A of said internal opening comprising a converging continuation of said opening 6. The central portion 173 of said opening is in this embodiment of constant diameter which then blends into a coaxial portion 17C of diverging diameter.

Fixed to the end of the venturi tube 17 by any convenient means, not shown, such as welding. is a barrel 18 having a series of process means comprising individual chamber units 19, 21 and 22. Each of said chamber units defines first a chamber of relatively large and constant cross section. followed next by a portion of con verging diameter and followed lastly by a portion of relatively small constant cross section. Particularly. the barrel unit 19 is provided with a portion 23 of constant internal diameter coaxially arranged and in communication with the section 17C of the venturi tube. the inlet opening of said barrel unit 19 of inlet opening 24 of the barrel unit I) being here a continuation of the walls defining said section 17C. The portion 23 of said barrel unit 19 then connects to a coaxial portion 26 of converging diameter which in turn connects to a relatively small portion 27 of constant diameter all thereof being coaxial with venturi tube I6. The portion 27 then connects to the next coaxially arranged barrel unit 21. same in this embodiment being identical with the parts 23, 26 and 27 ofthe unit I) and said unit 21 similarly connects to the coaxially placed barrel unit. or process means 22. which is identical to the barrel unit 21. As many such barrel units may be provided as are necessary to achieve the desired results and their specific diameters. convergence ratios. and other design features may be modified as desired to obtain the desired results. However the structure shown with the diameters. convergence. and number of units. as set forth in FIG. I of the drawing is effective for the purpose as desired.

The workpiece. wire. is caused to travel through the apparatus as indicated by the arrow A and a suitable abrasive grit carried by the liquid carrier. such as water, is introduced as a slurry through the passageway 13 into the chamber 2. Same is caused to swirl therein but is protected against contact with the wire until it passes through the relatively narrow construction defined by the tip 4 of the nozzlc and the surfaces 6 and 17A above described. At this point the flow of slurry has attained a reasonable degree of uniformity though not sufficient for a high level uniformity around the wire. However, as the slurry flows into each of the chambers of the barrel units I9. 21 and 22, same is first permitted to slow as it enters the larger diameter of each said chamber and then accelerate as it passes through the small diameter of each barrel unit. This slowing and acceleration together with the expanding and contracting of the compressed air component, all results in a very high degree of turbulence which turbulence is distributed uniformly around the wire. This re sults in a highly random bombardment of the wire by the particles carried within the slurry and hence a high degree of uniformity in treatment of the workpiece in question.

Turning now to FIG. 2, most of the parts are identical with those shown in FIG. 1 and are accordingly provided with the same numbers. Insofar as such numbers are identical with those of FIG. 1, they designate parts of the same shape and function as the embodiment of FIG. 1 and no further detailing thereof is necessary. There is in FIG. 2. however. shown a further annular member 3i surrounding the venturi tube [6 for defining an annular chamber 32 surrounding the venturi tube. A plurality of openings of which two are shown at 33 and 34 provide connection from the annular chamber 32 into the chamber within the barrel unit 19. A further supply of compressed air is introduced by the conduit 36 into the chamber 32 from which it flows through the passageways 33 and 34 and others similar into the chamber within the barrel unit I9. Said air tends to cause direct impingement of abrasive grits within said barrel unit onto the wire and in addition causes further turbulence and random flow of the grit carrying fluid stream within said barrel unit I).

Further and similar units similar to chamber 3I may be affixed to each of the other barrel units 2I and 22 if desired.

A typical use of the apparatus of FIGS. I and 2 is shown in FIG. 3. Here wire is withdrawn from a coil 4L passes through appropriate wire straightening rolls 42 and 43, is then led through the descaling unit 44 to a wind up roll 45. The source of compressed air. the source of the abrasive slurry and the means for withdrawing the abrasive slurry are all conventional insofar as the present apparatus is concerned and. while same will be utilized in the apparatus of FIG. 3, same is not shown.

The device embodying this invention can remove scale from wire or rod of hard steel at a line speed of I00 meters per minute.

Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes. it will be recognized that variations or modification of the disclosed apparatus. including the rearrangement of parts, lie within the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

I. In a device for guiding an abrasive slurry along and around an elongated workpiece and for ensuring uniform impingement of abrasive particles both circumferentially and longitudinally of said workpiece, the com bination comprising:

a workpiece guide for introducing a workpiece to and guiding same through said device in a predetermined position;

means defining a venturi coaxial with and axially spaced from said guide and means receiving an abrasive slurry and introducing same into said venturi;

process means defining at least one chamber coaxial with and communicating with the exit end of said venturi. said chamber having a first internal portion of diameter larger than that of said venturi and having a second portion coaxial and communicating therewith of diameter substantially less than that of first portion.

2. The device of claim 1 wherein there are a plurality of such process means surrounding said workpiece and serially connected with each other.

3. The device of claim I wherein the interior of at least some of said process means comprises three sections. namely, a first section of constant diameter larger than that of any portion of the venturi. secondly a sec tion of a progressively diminishing diameter coaxial with and axially connected to said first named section and a section of constant diameter coaxial with and connected to the exit end of said converging portion.

4. The device defined in claim I including also means defining an annular chamber surrounding at least one of said process means and passageways arranged around said chamber to effect communication from said annular chamber into said one chamber of said process means whereby turbulence of pressure gas introduced from said passageways into said last named chamber increases the agitation therein.

5. The device defined in claim 4 wherein said passageways define a plurality of converging pathways. 

1. In a device for guiding an abrasive slurry along and around an elongated workpiece and for ensuring uniform impingement of abrasive particles both circumferentially and longitudinally of said workpiece, the combination comprising: a workpiece guide for introducing a workpiece to and guiding same through said device in a predetermined position; means defining a venturi coaxial with and axially spaced from said guide and means receiving an abrasive slurry and introducing same into said venturi; process means defining at least one chamber coaxial with and communicating with the exit end of said venturi, said chamber having a first internal portion of diameter larger than that of said venturi and having a second portion coaxial and communicating therewith of diameter substantially less than that of first portion.
 2. The device of claim 1 wherein there are a plurality of such process means surrounding said workpiece and serially connected with each other.
 3. The device of claim 1 wherein the interior of at least some of said process means comprises three sections, namely, a first section of constant diameter larger than that of any portion of the venturi, secondly a section of a progressively diminishing diameter coaxial with and axially connected to said first nameD section and a section of constant diameter coaxial with and connected to the exit end of said converging portion.
 4. The device defined in claim 1 including also means defining an annular chamber surrounding at least one of said process means and passageways arranged around said chamber to effect communication from said annular chamber into said one chamber of said process means whereby turbulence of pressure gas introduced from said passageways into said last named chamber increases the agitation therein.
 5. The device defined in claim 4 wherein said passageways define a plurality of converging pathways. 